Will Apple's rumored iSlate tablet boast a 10-inch touchscreen? The masses seem to think so, but one technologist predicts a much smaller, 7-inch screen that's less power-hungry.

Next week, Apple unveils a tablet about which rumors have been swirling for the past year. Unlike Microsoft's tablet, no images or specs have been leaked. What will it look like?

If you're the betting type, here are some more good odds: the tablet will be called an iSlate, have much more capability than simply an e-reader, boast a 10-inch touchscreen and sell for less than $1,000. That's all well and good—but at least one technologist isn't convinced.

Not about a 10-inch touchscreen, anyway.

Aaron Vronko, CEO of Rapid Repair, an iPod and iPhone repair shop, took a hard look at hardware options for a tablet that would impact system performance, battery design and power capacity. His key conclusion: An Apple tablet won't debut with a 10-inch touchscreen, which has been widely predicted.

It's going to take a lot of juice to light up a 10-inch touchscreen for extended periods, such as when you're reading a book, he says. And poor battery life has been the bane of the iPhone, so it's unlikely Apple will make the same mistake with a tablet.

Other technologists agree that a 10-inch touchscreen would be quite a feat. NextWindow product marketing manager Geoff Walker, who has been involved with mobile computing and touchscreen technology for two decades, says a 10-inch touchscreen costs four times as much as a 3.5-inch iPhone touchscreen, thus it would jack up an Apple tablet's price tag.

If anyone should know about the technical workings of Apple mobile devices, it's Vronko. He literally wrote the book on caring for your iPhone 3GS and even has tips on how to improve battery life. Vronko was one of the first technicians to take apart the iPhone 3GS and author a repair guide.

Vronko talked to CIO.com and offered his predictions on the iSlate.

Aaron Vronko, CEO of Rapid Repair, loves taking apart Apple iPhones.

What do you think the widely rumored Apple tablet will look like?

Vronko: I expect this tablet device will be the next major step in the convergence of mobile technology, combining cell-phone convenience and simplicity with computer-like productivity, multi-tasking and flexibility in usage.

While the iPhone has broad consumer appeal and made major progress toward serving all our mobile and computing needs, it still lacked much of the productivity and multi-tasking of even a MacBook Air. This was due to limitations of form factor, user interface methods and hardware performance.

The Apple tablet, maybe called iSlate, will probably mirror the attractive, simple and easy-to-use iPhone yet have dramatically upgraded hardware and system performance. Hopefully, the tablet will also have a better means of interacting with the device, like an innovative keyboard that's faster than current two-thumbed typing.

Even with a much larger display, the tablet will still be highly mobile—that is, you'll probably be able to hold it in one hand—while being productive as an e-reader or document and photo editor.

What kind of display screen will it have?

Vronko: There has been a steady stream of rumors from various sources indicating both a 7-inch and a 10-inch screen size. While the 10-inch is doubtful for the first half of this year due to insufficient availability or production of key components, a 7-inch could be ready by the rumored March or early second quarter ship dates.

A 7-inch tablet would have four times the screen area of an iPhone. A conventional mobile LCD display easily consumes more power than any other component of the device and would severely hamper battery life—maybe only five hours of video—given Apple's preferred design constraints.

How can Apple get around the battery life issues that have plagued the iPhone?

Vronko: Look for Apple to follow Microsoft, Samsung and HTC in using an AM OLED (active-matrix organic light-emitting diode) display in their 7-inch tablet because of its ability to reduce power consumption. This could extend the battery life anywhere from 40 percent to 75 percent, depending on your usage.

While the technology suffers in sunlight, it shines more brightly and vibrantly than an LCD indoors. With clever software programming that emphasizes dark colors over light ones for large areas, AM OLED could save even more power, perhaps giving 25 hours or more when used as an e-reader.

The other good option would be a new hybrid technology, which has been developed by Pixel Qi. The technology works by stacking e-Paper technology made famous by the Amazon Kindle onto a mostly conventional LCD screen.

This technology saves battery power by reflecting ambient light in two of its three display modes instead of making its own. You have a low-cost, bright and full-color LCD when you need it and a limited-color or high-contrast monochrome display that is smartly controlled by the application. All of which could allow e-reader functionality for maybe 30 hours!

What will power this tablet?

Vronko: Apple will have to beef up the hardware inside this tablet from what the last iPhone offered in order to provide the kind of multi-functional power people expect from a device in its rumored price range, $700 to $1000.

Thanks to its April, 2008 acquisition of startup processor designer PA Semi, I think Apple has the team and skill to do just that.

It has been long speculated and even hinted at by company representatives that the PA Semi team is working on a System-on-a-Chip (SoC) application processor to serve as the heart of future Apple mobile devices. Expect the SoC platform in a 7-inch tablet to include twin CPUs of ARM's latest high-speed and power saving design, the Cortex-A9.

The device will also need significantly improved graphics processing power to drive up to a million pixels in the display and still render 3D games and applications without problems. After recently buying a long-term design license with mobile GPU designer Imagination Technology, expect this to be the recently unveiled PowerVR SGX545 or possibly SGX540.

Altogether, the highly integrated application processor will likely feature seven to 10 different processor cores, including HD-video encoder/decoders for playing and recording content in 720p or higher. (720p refers to 720 pixels of vertical resolution, while the letter p stands for progressive scan.)

The dual CPUs, other upgraded cores and improved design could give the tablet two to three times more horsepower than last summer's iPhone 3GS, while keeping effective power consumption of the core system nearly unchanged. All of this contributes to longer battery life.

Do you foresee replaceable batteries?

The exterior look and form will attempt to marry the best elements of its extremely popular iPhone and Mac unibody designs. Expect Apple to help meet design goals by sticking with a non user-replaceable battery that's only about half the size of an average netbook power pack.

Battery times for most functions will be on par with the latest iPhone but improve dramatically for apps that make use of the new tech, such as an e-reader.

Tom Kaneshige is a senior writer for CIO.com in Silicon Valley. Send him an email at tkaneshige@cio.com. Or follow him on Twitter @kaneshige. Follow everything from CIO.com on Twitter @CIOonline.